| far-fetched(uncertain, doubtful, unsure) |
| fast and loose(adjective, unreliable, insecure, treacherous, incalculable) |
| fearful(adjective, modest, nervous, humble, shy) |
| fishy(uncertain, doubtful, unsure) |
| fluctuant(adjective, uncertain, nervous, doubtful, shaky) |
| hazardous |
| hesitant(adjective, uncertain, modest, nervous, humble) |
| hopeless(adjective, unreliable, insecure, treacherous, incalculable) |
| improbable(uncertain, doubtful, unsure) |
| in a quandary(expression, adjective, idiom, uncertain, nervous) |
| incalculable(adjective, unreliable, insecure, treacherous) |
| inconstant(loose, unpredictable, unreliable, fickle, variable) |
| indecisive(uncertain, nervous, doubtful, insecure, unsure) |
| indeterminate(adjective, careless, loose, uncertain, nervous) |
| introvert(adjective, modest, nervous, humble, hesitant) |
| introverted(adjective, modest, nervous, humble, hesitant) |
| irresolute(uncertain, nervous, shy, doubtful, fearful) |
| jumpy(uncertain, nervous, insecure, unsure, self-doubting) |
| lacking(adjective, uncertain, nervous, doubtful, shaky) |
| loner(adjective, modest, nervous, humble, hesitant) |